Heat exchanger comprising plates with two different sides for the media

Abstract

Heat exchanger (100), preferably for a motor vehicle, comprising: at least one first plate (P1), at least one second plate (P2), wherein the at least two plates (P1, P2) have a bottom plane (B1, B2), wherein the at least two plates (P1, P2) are arranged alternately one above the other or next to the other.According to the invention, it is provided that the at least two plates (P1, P2) each have a plurality of beads (S1, S2), wherein the beads (S1, S2) are each spaced apart from one another, wherein the beads (S1, S2) each extend in an extension direction away from the main surface (H1, H2), so that channels (K1, K2) are formed between two adjacent plates (P1, P2) each having at least one hydraulic diameter (HD1, HD2) when the heat exchanger (100) is assembled, wherein the hydraulic diameters (HD1, HD2) change along the length of the channels (K1, K2), wherein the hydraulic diameter (HD1) of the first channels (K1) is greater than the hydraulic diameter (HD2) of the second channels (K2).

Description

[0001] The invention relates to a heat exchanger consisting of two types of plates, as well as the use of the heat exchanger in a coolant circuit and / or a refrigerant circuit, preferably for a motor vehicle.

[0002] The document DE 10 2004 036 951 A1 discloses a heat exchanger for motor vehicles, wherein the disclosed heat exchanger is formed from interconnected plates. Externally closed cavities are formed between the plates, each of which has at least two first openings and two second openings (an inlet line and an outlet line) through which a first medium and a second medium flow alternately. The plates have beads (are profiled in such a way) that connection points (contact points) occur between the plates, in the region of which the plates are connected (fastened) to one another. According to the invention, the beads (profiles) of the plates and their connection points are shaped in such a way that the flow of the first and second medium from the corresponding first opening to the corresponding second opening does not proceed in a straight line.The disclosed plates have a repeating profile which extends substantially transversely to the main flow direction and, in particular, are corrugated in a zigzag shape around a direction of extension. The beads (profiles) divide the cavities between two adjacent plates into channels through which the first medium and the second medium flow. A pair of the openings each have domes (bores) perpendicular to the base plane. The domes are raised in such a way that a fluidic connection is created from one dome alternately to every second cavity between adjacent plates. In this way, two fluidically separated flow paths are created through the disclosed heat exchanger. Since the beads (profiles) of the plates are geometrically identical, the channels also have the same hydraulic diameter.The disclosed plates each have four openings with the same hydraulic diameter. The disclosed heat exchanger has two flow paths with the same hydraulic diameter. It is possible for the disclosed heat exchanger to be used in a refrigerant circuit, with the first medium being a coolant and the second medium being a refrigerant. There is discussion about prescribing the use of carbon dioxide as a refrigerant in a European Union directive. When using carbon dioxide as a refrigerant in a refrigerant circuit, the pressure can be three to four times higher than when using refrigerants currently in series use, such as R1234yf. A medium containing glycol, for example, can be used as the coolant. The coolant typically has a pressure of 2 bar to 3 bar.The pressure of the refrigerant can be up to 30 times higher than the pressure of the coolant when carbon dioxide is used as the refrigerant. The high pressure of the refrigerant stresses the beads (profiles) and the connection points. Two adjacent plates are geometrically identical, and the channels have the same hydraulic diameter. Due to the high pressure of the refrigerant in the channels, the surfaces of the channels are subjected to high stress, thus adversely reducing the strength of the disclosed plates and the disclosed heat exchanger. The high pressure of the refrigerant on the connection points can lead to undesirable leaks in the disclosed heat exchanger. The refrigerant can flow through the disclosed heat exchanger in gaseous form, which adversely increases the risk of leaks even further, as it is more difficult to create a gas-tight connection than a liquid-tight connection.The profiles and thus the channels between two adjacent plates are geometrically identical, for this reason, the turbulences and vortices occurring in the flow of the two media cannot be influenced independently in a detrimental way in order to improve the heat transfer between the two media.

[0003] The device according to the invention with the features of the independent patent claim has the advantage that the plates and the heat exchanger have a high strength and the heat transfer between the two media is improved, thus increasing the performance of the heat exchanger.

[0004] The starting point for the invention is a heat exchanger having a plurality of plates arranged one above the other or next to one another. The heat exchanger according to the invention, preferably for a motor vehicle, has at least one first plate and at least one second plate. The at least two plates each have a base plane. The at least two plates are arranged alternately one above the other or next to one another. Two media flow through the heat exchanger on two fluidically separate flow paths so that the two media can transfer heat to one another. The at least two plates can be arranged alternately between a lower cover plate and an upper cover plate. All of the plates together form the block of the heat exchanger according to the invention. The block height of the heat exchanger according to the invention is measured from the lowest plate to the top plate.The at least two plates can each have a rectangular shape. It is conceivable for the at least two plates to each have a shorter side and a longer side. Alternatively, it is conceivable for the at least two plates to each have a square shape with two sides of substantially equal length. According to the invention, the at least two plates each have a plurality of beads, each extending in an extension direction away from the base plane. Wherein the beads are spaced apart from one another, so that channels, each having at least one hydraulic diameter, are formed between two adjacent plates when the heat exchanger is assembled. Wherein the hydraulic diameters change along the length of the channels. Wherein the hydraulic diameter of the first channels is greater than the hydraulic diameter of the second channels.It is possible for the hydraulic diameter of the first channels to be at least twice as large as the hydraulic diameter of the second channels. An assembled heat exchanger is understood to mean that, for example, first plates and second plates are arranged alternately one above the other and are connected to one another, so that the heat exchanger can have two fluidically separate flow paths for two media and can be used in a refrigerant circuit and / or a coolant circuit of a motor vehicle. The total cross-sectional area of the channels can be approximated by a hydraulic diameter. The hydraulic diameter is a calculation parameter that can be used when the cross-section of a pipe or channel deviates from a circle. The hydraulic diameter can be used, for example, to calculate the pressure loss in the flow paths or the throughput of the media in the flow paths.Fluidically separated means that only a negligible amount of a medium can pass through the connection.

[0005] There is discussion about prescribing the use of carbon dioxide as a refrigerant in a European Union directive. When carbon dioxide is used as a refrigerant in a refrigerant circuit, the pressure can be three to four times higher than when using refrigerants currently in series production, such as R1234yf. A coolant that is, for example, a mixture of glycol and water can be used as the first medium. In a first embodiment of the heat exchanger according to the invention, the coolant flows through the first flow path and thus the first channels as the first medium. The refrigerant, preferably carbon dioxide here, flows through the second flow path and thus the second channels. The coolant (first medium) generally has a pressure of 2 bar to 3 bar.The pressure of the refrigerant (second medium) can be up to 30 times higher than the pressure of the coolant when carbon dioxide is used as the refrigerant. The high pressure of the refrigerant (second medium) puts loads on the beads and the connection points. The second channels each have lateral surfaces. The second medium can flow through the second channels. Carbon dioxide can have three to four times the pressure than media currently used in series. The three to four times higher pressure loads the lateral surfaces of the second channels. Since the cross section of the second channels is smaller than the cross section of the first channels, the lateral surfaces of the second channels are also smaller. In this way, the surfaces of the at least two plates loaded by the three to four times higher pressure are smaller and the strength of the plates is advantageously increased.Two adjacent plates can be joined together at the beads in a material-to-material bond, for example by brazing. Since the second channels have a significantly smaller cross-section than the first channels, the areas of the second channels that are parallel to the flat surfaces (the flat surfaces oriented longitudinally and transversely) are also significantly smaller. The carbon dioxide can only flow through the second channels and only subject these surfaces to the high pressure. Since the surfaces are small, only a small load or at least a significantly reduced load can occur at the connection points (soldering points), thus increasing the strength of the heat exchanger. The carbon dioxide can flow through the heat exchanger according to the invention in gaseous form.Since the stress on the joints can be reduced, a heat exchanger can be created that has a high gas tightness and avoids a possible loss of a gaseous medium.

[0006] A gaseous medium can flow through the first channels and thus through the first flow path of the heat exchanger according to the invention. The large hydraulic diameter of the first channels can at least reduce the pressure loss that occurs in the first flow path. The pressure loss is the pressure difference that occurs and can depend on the cross-section of the channel or pipe as well as the pressure, since cross-sections that are too small act like a throttle. Pressure losses in a coolant circuit can have an undesirable influence on the boiling point of the coolant used (here the first medium). This is because the boiling temperature and the boiling pressure are interdependent. The pressure loss increases exponentially over the volume flow of a medium. A pressure loss corresponds to an energy loss. Strength is understood to be the mechanical load-bearing capacity of a plate or connection until the plate or connection fails.For example, a fracture or excessive permanent deformation of the plate can cause this failure.

[0007] The at least one first plate differs geometrically from the at least one second plate. The beads are each offset from one another in the longitudinal direction and the transverse direction. The first beads of the at least one first plate are offset longitudinally from the second beads of the at least one second plate such that the cavities between two adjacent plates are divided into channels. The first beads of the at least one first plate are each offset longitudinally from the second beads of the at least one second plate such that the beads overlap in the direction of extent. The direction of extent is essentially perpendicular to the floor plane. Essentially is understood to mean a maximum possible angular deviation of ±10° and a length deviation of ±2 mm. It is possible for the at least two plates to each have a stacking direction, a transverse direction and a longitudinal direction.The stacking direction can run in the direction of the block height of the assembled heat exchanger, and the transverse direction and the longitudinal direction can run along the sides of the at least two plates. Due to the offset arrangement of the first beads relative to the second beads, turbulence and vortexes can be generated independently in the flow of the two media, thus advantageously improving the heat transfer between the two media. It is possible for the individual distances between the beads to be unequal, thus simplifying the generation of turbulence and vortexes.

[0008] According to a preferred embodiment of the invention, the beads each have an elongated shape. The beads form the channels between two adjacent plates for the two media. The beads each have two sides. One of the two sides is significantly longer than the other side. In the first embodiment of the invention, the at least two plates each have a rectangular shape. The longer sides of the beads and the longer side of the at least two plates can in this case be essentially parallel to one another. The elongated shape of the beads forms the second channels with a hydraulic diameter that has high strength against internal loading with high pressure. The second channels have an advantageous small diameter and the at least partially circular shape is well suited to high pressure loading.It is possible for the beads to be of different lengths. This allows sections of the channels to be represented that are of different lengths, thus further improving the generation of turbulence and vortices.

[0009] In a further embodiment of the invention, the beads are each arranged essentially in rows parallel to the main flow direction of the two media. The main flow direction of the two media is determined by the arrangement of the openings in the at least two plates. Due to the advantageous arrangement of the beads in parallel rows, the two media are distributed over almost the entire surface of the at least two plates. In this way, almost the entire surface of the plates participates in the heat transfer. The performance of a heat exchanger is determined by the size of the surface of the plates and the most even possible distribution of the media over this surface. The beads enlarge the surface of the plates and thus increase the performance of the heat exchanger according to the invention. In the first embodiment of the at least two plates according to the invention, the two first openings are arranged opposite one another on the shorter sides.The second openings are each arranged between the beads and the first openings. In this case, the main flow direction of the two media runs along the longer side. The at least two plates can, for example, each have 13 rows of beads. It is also conceivable for the first openings and the second openings to be arranged diagonally opposite one another. In this case, the main flow direction of the two media runs diagonally to the longer side of the at least two plates.

[0010] According to a preferred embodiment of the invention, one of the beads is offset from the adjacent beads in and / or against the main flow direction. As a result of this measure, the flow of a medium in a channel is deflected several times. As a result of the overlap of the first beads and the second beads, the flow of a medium in a channel is advantageously deflected out of the bottom plane of the plates. The numerous changes in direction of the medium in a channel create additional and / or greater turbulence and vortexes, which further improve the heat transfer between the two media. As a result of the arrangement of the beads, the flow of the second medium in the second channels is deflected transversely and longitudinally to the main flow direction.

[0011] In a further embodiment of the invention, the at least two plates each have at least one first opening which is arranged in a first flat part of the base plane. At least one first guide bead in each case runs to the at least one first opening, which in each case extends away from the base plane in the direction of extension, so that first guide channels are formed between two adjacent plates, via which first guide channels the first medium is distributed to the first channels and collected again when the heat exchanger is assembled. The base planes of two adjacent plates lie on top of one another. The thickness of the at least two plates results in the enclosure of the at least one first opening. The flow of the first medium into or out of the first channels can be impeded or blocked by the high enclosure of the at least one opening.The first guide channels improve the distribution of the first medium across all of the first channels. In this way, the first medium is distributed over the entire surface of the at least two plates, and thus almost the entire surface of the at least two plates participates in the heat transfer between the two media. The collection of the first medium from the first channels at the second first opening is also improved by the first guide channels. At the end near the beads, the first guide channels each have an opening through which the first medium flows out of the first guide channel. The direction of extension of the first guide beads is essentially perpendicular to the base plane. The first flat part of the base plane of the at least two plates is loaded by the pressure of the first medium. The first flat part of the base plane is supported on the first guide beads, and in this way the strength of the plates is increased even further.

[0012] In the first embodiment of the heat exchanger according to the invention, the at least two plates each have two first openings. The two first openings are each oval and extend along the shorter side of the at least two plates. Four first guide beads, and thus four first guide channels, run into each of the two first openings when the heat exchanger is assembled. The at least two plates each have eight guide beads.

[0013] In a further embodiment of the invention, the at least two plates each have at least one dome, which extends in the direction of extension away from the base plane. The at least one dome surrounds a second opening, with at least one of the beads running to the at least one dome, so that the second medium is distributed between the second channels and collected again when the heat exchanger is assembled. Since the beads run into the second openings, the second medium is distributed between the second channels and collected again. The beads and thus also the channels are arranged in several parallel rows. In this way, the second medium is distributed over the entire surface of the plates, and thus almost the entire surface of the at least two plates participates in the transfer of heat between the two media. The domes fluidically separate the two flow paths of the heat exchanger from one another.

[0014] Furthermore, it is possible for the first hydraulic diameter to be at least twice as large as the second hydraulic diameter. The first medium can flow through the heat exchanger according to the invention in gaseous form. The first hydraulic diameter of the first channels is at least twice as large as the second diameter of the second channels. The first channels, together with the first openings, form the first flow path of the heat exchanger according to the invention. By making the first hydraulic diameter at least twice as large, the pressure loss in the first flow path can be reduced even further. The pressure loss that occurs in a coolant circuit or refrigerant circuit influences the boiling point of the first medium via the resulting pressure, and thus undesirable changes in the boiling point can be avoided by reducing the pressure loss that occurs.

[0015] Furthermore, it is possible for the at least one first opening to be larger than the at least one second opening. In this way, the hydraulic diameter of the first flow path can be increased, thus further reducing the resulting pressure loss in the first flow path. The risk that the resulting pressure loss in the first flow path of the heat exchanger according to the invention influences the boiling point of the first medium via the pressure occurring in a coolant circuit or refrigerant circuit can thus be further reduced.

[0016] Furthermore, it is possible for the number of second openings to be greater than the number of first openings. By dividing the second openings into several openings, the area of an individual second opening can be reduced while maintaining the same hydraulic diameter of the second flow path at this point, while maintaining a round shape for the second opening. Since the area is reduced, the high pressure of the second medium acts on a smaller area, and the round shape of the second openings can increase the strength of the at least two plates and of the heat exchanger according to the invention. In the first embodiment of the at least two plates according to the invention, the plates each have eight domes and second openings. Four domes with second openings are arranged in a row along the shorter side between the first opening and the beads.The upper cover plate may have channels through which the second medium can be distributed to the second openings and collected again.

[0017] In a further embodiment of the invention, the first beads, the at least one first guide bead, and the at least one first dome are each raised relative to the first base plane of the at least one first plate. The at least one first bead and the at least one first guide bead are formed as groove-shaped elevations relative to the first base plane. The at least one first dome can be formed as a truncated cone, the diameter of which is largest in the first base plane. The direction of extension of the at least one first plate is substantially perpendicular to the first base plane and is oriented in the direction of the block height of the assembled heat transfer element (from the lower cover plate to the upper cover plate). It is possible for the direction of extension of the at least one first plate to be oriented in the stacking direction.

[0018] In a further embodiment of the invention, the second beads, the at least one second guide bead, and the at least one second dome are each recessed relative to the second base plane of the at least one second plate. The at least one second bead and the at least one second guide bead are each formed as a groove-shaped recess relative to the second base plane. The at least one second dome can be formed as a truncated cone, the diameter of which is largest in the second base plane. The direction of extension of the at least one second plate is substantially perpendicular to the second base plane and is oriented opposite to the block height of the assembled heat transfer device (from the upper cover plate to the lower cover plate). It is possible for the direction of extension of the at least one second plate to be oriented opposite to the stacking direction.

[0019] According to a preferred embodiment of the invention, the first flat parts of the base plane of two adjacent plates are each connected to one another when the heat exchanger is assembled. The first flat parts of the base plane of a plate are loaded by the pressure of at least one of the two media. Since the first flat parts have no measures to increase the strength in these areas, these areas are often subject to high loads. Measures to increase the strength could be, for example, the arrangement of further beads or folds in these areas. Since the first flat parts of the base plane always lie on top of one another and are connected to one another, the material thickness in these first areas of the base plane is advantageously doubled and the strength of the plates in these areas is increased.The first medium flows through the at least one first opening and is then, for example, distributed among the first channels or collected again. Since the second openings are arranged between the first opening and the beads, the first flat parts of the base planes are each only exposed to the first medium. In this way, stress caused by two different media pressures in the first flat part of the base plane can be avoided. The stress on the at least two plates can be further reduced, and the strength of the at least two plates can be further increased.

[0020] According to the invention, the at least two plates of the heat exchanger according to the invention each have a circumferential raised edge. The edges, the beads, the guide beads, the base planes and the domes of two adjacent plates are connected to one another. Since two adjacent plates are connected to one another at the edges, the cavities created between the plates are fluidically separated from the environment. Since the domes and the base planes of adjacent plates are connected to one another, the two flow paths of the heat exchanger according to the invention are fluidically separated from one another. The beads divide the cavities between two adjacent plates into channels. The at least two plates can each be formed in one piece. For example, the at least two plates can each be made from a metal disc.It is possible for the at least two plates to be produced using a stamping process. Alternatively, it is conceivable for the at least two plates to be punched. The openings can be produced at the same time as the at least two plates are stamped or punched. The at least two plates comprise a metallic material. It is possible for the at least two plates to comprise an aluminum alloy. Alternatively, it is conceivable for the at least two plates to comprise a precious metal. It is conceivable for the plates to be joined in a material-to-material bond by means of brazing. The at least two plates could, for example, be solder-plated. The soldering of the at least two plates can take place under vacuum. Alternatively, the at least two plates can be joined using an adhesive. For this purpose, the plates can be laminated with an adhesive layer before bonding.The raised, circumferential edge can be used to fix the at least two plates together before the brazing or gluing process. At least one of the at least two plates can have a step on the edge. For example, the at least one first plate can have the step on the edge. This step can be pronounced all the way around or in sections. An adjacent plate does not rest on the step. The step can reduce the stiffness of a first plate. In this way, it can be ensured that the at least two plates lie on top of each other without any gap.

[0021] In a first use according to the invention, the heat exchanger according to the invention can be used in a coolant circuit of a motor vehicle. The coolant circuit according to the invention can have a heat source, a coolant, a heat exchanger according to the invention, a pump, and an expansion valve. It is conceivable that the heat exchanger according to the invention is used as an oil cooler. In order to prevent aging of the oil in motor vehicles, it is necessary to dissipate heat as consistently as possible. In the heat exchanger according to the invention, the heat of the oil (first medium) can be transferred to a coolant (second medium). Carbon dioxide (R744) can be used as the coolant. There is discussion about prescribing the use of carbon dioxide in a coolant circuit for a motor vehicle in a European directive.Carbon dioxide has a lower global warming potential than currently used refrigerants or coolants in series production and does not damage the ozone layer. Carbon dioxide can have a pressure three to four times higher than currently used media in series production, such as R1234yf. The carbon dioxide can flow in gaseous form through the heat exchanger according to the invention. The carbon dioxide can be moved through the coolant circuit by means of the pump. The pump generates a pressure that transports the coolant from the heat source to the heat exchanger according to the invention and back. The expansion valve regulates the pressure and temperature of the coolant circulating through the coolant circuit according to the invention. The first medium (for example oil) flows through the first flow path and the carbon dioxide (R744, coolant) flows through the second flow path, which has the second channels with the at least one second hygric diameter.The surfaces of the second channels are small. This way, the high pressure of the carbon dioxide is applied only to the small surfaces of the second channels and thus also to the small surfaces of the beads. High stress on the beads and the joints between two adjacent plates can thus be advantageously avoided, thus producing a heat exchanger according to the invention with high strength.

[0022] In a second use according to the invention, the heat exchanger according to the invention can be used in a refrigerant circuit for a motor vehicle. A refrigerant can flow through the refrigerant circuit according to the invention. Carbon dioxide (R744) can be used as the refrigerant. There is discussion about prescribing the use of carbon dioxide in a coolant circuit for a motor vehicle in a European directive. Carbon dioxide has a lower global warming potential than refrigerants or coolants currently used in series and does not damage the ozone layer. Carbon dioxide can have a pressure three to four times higher than media currently used in series, such as R1234yf. The refrigerant circuit according to the invention can have at least one (first) heat exchanger according to the invention, a compressor, an expansion valve and a further (second) heat exchanger.It is possible for the refrigerant circuit according to the invention to have two heat exchangers according to the invention. In this case, the first heat exchanger according to the invention can be operated as an evaporator, in which heat is transferred from a first medium to the liquid refrigerant (second medium) by evaporating the refrigerant (second medium) on the first medium. In the compressor, the at least largely vaporous refrigerant is compressed. The second heat exchanger according to the invention can be operated as a condenser, in which heat is transferred from the hot vaporous refrigerant to another (first) medium by condensing the refrigerant on the other medium. The other medium can be a mixture of glycol and water. The cool liquid refrigerant is expanded in the expansion valve and flows back to the first heat exchanger.The carbon dioxide (R744, refrigerant) flows through the second flow path of the heat exchanger according to the invention, which has the second channels with at least one second hygric diameter. The surfaces of the second channels are small. In this way, the high pressure of the carbon dioxide is applied only to the small surfaces of the second channels and thus also to the small surfaces of the beads. High stress on the beads and the connection points between two adjacent plates can thus be advantageously avoided, and the heat exchanger according to the invention can thus be produced with high strength.

[0023] In a third use according to the invention, the heat exchanger according to the invention can be used in a coolant circuit and in a refrigerant circuit, each for a motor vehicle. The motor vehicle can have an at least partially electric drive. A coolant that is a mixture of water and glycol can flow through the coolant circuit according to the invention. Carbon dioxide (R744) can be used as the refrigerant. There is discussion about prescribing the use of carbon dioxide in a coolant circuit for a motor vehicle in a European directive. Carbon dioxide has a lower global warming potential than refrigerants or coolants currently used in series production and does not damage the ozone layer. Carbon dioxide can have a pressure three to four times higher than media currently used in series production, such as R1234yf.In motor vehicles with at least partial electric drive, the battery and the electric drive motor should always be kept at a constant temperature in order to achieve the longest possible service life and maintain full performance. At high ambient temperatures, the performance of the cooler in the coolant circuit may not be sufficient for this. In this case, the first flow path of the heat exchanger according to the invention can be integrated into the coolant circuit and the second flow path can be integrated into the refrigerant circuit. Since the refrigerant (here carbon dioxide) is cooler, the coolant can be cooled down sufficiently that the battery and the drive motor can be kept at a constant temperature. The heat exchanger according to the invention is thus used as a chiller.The carbon dioxide (R744, refrigerant) flows through the second flow path of the heat exchanger according to the invention, which has the second channels with at least one second hygric diameter. The surfaces of the second channels are small. In this way, the high pressure of the carbon dioxide is applied only to the small surfaces of the second channels and thus also to the small surfaces of the beads. High stress on the beads and the connection points between two adjacent plates can thus be advantageously avoided, and the heat exchanger according to the invention can thus be produced with high strength.

[0024] They show: Fig. 1.1: A plan view of a first plate in a first embodiment according to the invention. Fig. 1.2: A plan view of a second plate in a second embodiment of the invention. Fig. 2: A top view of four plates according to the invention stacked on top of each other. Fig. 3.1: A sectional view along section plane 1 of four stacked plates according to the invention. Fig. 3.2: A sectional view along the cutting plane 5 of four plates according to the invention stacked on top of each other. Fig. 3.3: A sectional view along the cutting plane 4 of four plates according to the invention stacked on top of each other. Fig. 3.4: A sectional view along the section plane 3 of four stacked plates according to the invention. Fig. 3.5: A sectional view along section plane 1 of four stacked plates according to the invention. Fig. 4: A top view of a heat exchanger according to the invention in the assembled state.

[0025] Fig. 1 shows a first plate P1 in a first embodiment according to the invention and a second plate P2, also in a first embodiment according to the invention. The plates P1, P2 each have a rectangular shape with a longer and a shorter side. The material of the plates P1, P2 is a metallic material. Preferably, the plates P1, P2 each comprise an aluminum alloy. It is possible for the plates P1, P2 to be produced using an embossing process. Alternatively, it is possible for the plates P1, P2 to be produced using a punching process. The plates P1, P2 each have a base plane B1, B2. The plates P1, P2 each have a circumferential raised edge RA. The two plates P1, P2 each have a plurality of beads S1, S2, each extending in an extension direction away from the base plane B1, B2.The direction of extension is essentially perpendicular to the base plane B1, B2 and can run in or against the block height of the heat exchanger (not shown). The beads S1, S2 are spaced apart from one another. The minimum distance between two individual beads S1, S2 is 3 mm. The beads S1, S2 each have an elongated shape. The length of an individual bead S1, S2 is at least 5 mm, preferably 10 mm. The plates P1, P2 each have two first openings O11, O21, each having an oval, elongated shape and extending almost along the entire shorter side of the plates P1, P2. Plates P1, P2 each have eight guide beads SO11, SO21, each extending in an extension direction away from the base plane B1, B2. Four of the guide beads SO11, SO21 are arranged along one of the longer sides of one of the four first openings O11, O21.The guide beads SO11, SO21 each run into the first openings O11, O21 and each have an opening at the end. In this way, blockage of the flow of a first medium (not shown) by the edge of the first opening can advantageously be avoided by allowing the first medium (not shown) to flow along the guide beads SO1, SO2. The plates P1, P2 each have eight domes D1, D2, which each extend in the direction of extension away from the base plane B1, B2. The domes D1, D2 each surround a second opening O12, O22. The second openings O12, O22 are circular, and the domes D1, D2 are each annular around the second openings O12, O22. At least one bead S1, S2 runs into the domes D1, D2. The main flow direction H of the two media not shown runs essentially along the longer side of the plates P1, P2 from the first openings O11, O22 respectively.from the second openings O12, O22. The beads S1, S2 are elongated along the main flow direction H. The beads S1, S2 are offset from one another along the main flow direction H and transversely to the main flow direction H. The stacking direction SR runs along the block height of the heat exchanger (not shown) and is essentially perpendicular. The transverse direction QR runs along the shorter side of the plates P1, P2 and the longitudinal direction LR runs along the longer side of the plates P1, P2. The transverse direction QR and the longitudinal direction LR are each essentially orthogonal to the stacking direction SR. The main flow direction H and the longitudinal direction LR coincide. Essentially is understood to mean a maximum possible angular deviation of ±10° and a length deviation of ±2 mm.

[0026] Shown are Fig. 1.1 a first plate P1 in a first embodiment according to the invention. The first beads S1 and the first guide beads SO1 are formed as groove-shaped elevations, and the first domes D1 are raised relative to the first base plane B1. Essentially, the first beads S1, the first guide beads SO1, and the first domes D1 have the same length in the direction of extension, which here coincides with the stacking direction SR or is formed along the block height of the assembled heat exchanger (not shown).

[0027] Shown are Fig. 1.2 a second plate P2 in a first embodiment according to the invention. The second beads S2 and the second guide beads SO2 are formed as groove-shaped depressions, and the second domes D2 are recessed relative to the second base plane B2. Essentially, the second beads S2, the second guide beads SO2, and the second domes D2 have the same length in the direction of extension, which here runs counter to the stacking direction SR or is formed counter to the block height of the assembled heat exchanger (not shown).

[0028] In Fig. Figure 2 shows a plan view of four plates P1, P2 arranged one above the other in a first embodiment according to the invention. A second plate P2 is arranged at the bottom, and the other three plates P1, P2 are stacked alternately on top of one another. At the connection points between two adjacent plates P1, P2, the plates P1, P2 are integrally connected to one another. Between two adjacent plates P1, P2, connection points occur at the edges, beads, guide beads, and domes (not shown), and the adjacent plates P1, P2 are connected to one another at these connection points. It is conceivable that the plates P1, P2 are connected to one another by means of brazing. The plates P1, P2 have a rectangular shape with a shorter side and a longer side.The stacking direction SR runs along the block height of the four plates P1, P2 and the transverse direction QR runs along the shorter side of the plates P1, P2 and the longitudinal direction LR runs along the longer side of the plates P1, P2. The main flow direction H of two media not shown runs essentially along the long side of the plates P1, P2. The four plates P1, P2 each have four first openings O11 (some not shown) and the four plates P1, P2 each have eight second openings O12 (some not shown). The first cutting plane 1 runs down the middle of the shorter side.

[0029] The second cutting plane 2 runs through the center of the first openings (partially not shown). The third cutting plane 3 runs centrally through the second openings (partially not shown). The fourth cutting plane 4 runs parallel to the third cutting planes 2 to 3, partially through the beginning and end of the partially not shown beads. The fifth cutting plane 5 runs parallel to the cutting planes 2 to 4, partially centrally through partially not shown beads.

[0030] Shown are Fig. 3 shows the section along the five cutting planes in Fig. 2 of four plates P1, P2 arranged one above the other. The four plates P1, P2 are each shown in the first embodiment according to the invention. A second plate P2 is arranged at the bottom. The three further plates P1, P2 are stacked alternately above it. The stacking direction SR runs along the block height of the plates P1, P2 or the assembled heat exchanger (not shown).

[0031] In Fig. 3.1 is the section along the first section plane 1 (shown in Fig. 2). Since the first corrugations S1 are offset from the second corrugations S2 along the main flow direction H or the longitudinal direction LR, the second channels K2 are formed between two adjacent plates P2, P2. The second medium M2 is distributed to the second channels K2 via the second openings O12, O22 and collected again. The hydraulic diameter is a calculated value that can be used when the cross-section of a pipe or channel deviates from a circle.

[0032] In Fig. 3.2 is the section along the fifth section plane 5 (shown in Fig. 2). The beads S1, S2 are each spaced apart. Since the first beads S1 are pronounced as elevations and the second beads S2 as depressions, the cavities created between two adjacent plates P1, P2 are each divided into first channels K1 and second channels K2. The channels K1, K2 each have a hydraulic diameter HD1, HD2. Using the hydraulic diameter, the diameter can be approximated to a circle if the cross-section of a pipe or channel deviates from a circle. The first hydraulic diameter HD1 of the first channels K1 is larger than the second hydraulic diameter HD2 of the second channels K2. The second channels K2 each have a semicircular second hydraulic diameter HD2 because the illustrated first beads S1 of the first plates P2 each lie on a flat area of the second plates P2.

[0033] In Fig. 3.3 is the section along the fourth section plane 4 (shown in Fig. 2). The beads S1, S2 are each spaced apart. Since the first beads S1 are pronounced as elevations and the second beads S2 as depressions, the cavities created between two adjacent plates P1, P2 are each divided into first channels K1 and second channels K2. The channels K1, K2 each have a hydraulic diameter HD1, HD2. The first hydraulic diameter HD1 of the first channels K1 is greater than the second hydraulic diameter HD2 of the second channels K2. The second channels K2 each have a substantially circular second hydraulic diameter HD2, since the illustrated first beads S1 of the first plates P2 each lie on the second beads S2 of the second plates P2.

[0034] In Fig. 3.4 is the section along the fourth section plane 3 (shown in Fig. 2). Domes D1 and D2 each surround the second openings O12 and O22. The second medium (not shown) is distributed to the second channels and collected again via the second openings O12 and O22.

[0035] In Fig. 3.5 is the section along the second section plane 2 (shown in Fig. 2). The first openings O11, O21 are each shown in section. The first guide beads SO1 of the first plates P1 lie on the second guide beads SO2 of the second plates P2. Since the first guide beads SO1 are each designed as elevations and the second guide beads SO2 are each designed as depressions, first guide channels KV1 are formed between two adjacent plates P1, P2. A first medium (not shown) flows through the first guide channels KV1 and is distributed via the first openings O11, O21 and collected again. Since two plates P1, P2 always lie in the area of the first openings O11, O21, the flow of the first medium (not shown) can be obstructed (blocked) by the double material thickness. The first guide channels KV1 at least reduce this obstruction to the flow of the first medium (not shown).Advantageously, the first flat part of the bottom plane of the plates is supported on the first guide beads SO1, SO2, thus further increasing the strength of the plates.

[0036] Shown in Fig.4 is a plan view of a heat exchanger 100 in a first embodiment according to the invention. The first plates P1 and the second plates P2 are arranged alternately between the lower cover plate UAP and the upper cover plate OAP. The block height of the heat exchanger according to the invention is measured between the lower cover plate UAP and the upper cover plate OAP. The stacking direction SR runs from the lower cover plate UAP to the upper cover plate OAP along the block height of the heat exchanger 100 according to the invention. The beads (not shown) create two fluidically separated flow paths (not shown) in the heat exchanger 100. The first medium M1 is fed into the heat exchanger 100 via the first inlet line ZA1 and is discharged from the heat exchanger 100 again via the first outlet line AA1.The second medium M2 is fed into the heat exchanger 100 via the second inlet line ZA2 and is discharged from the heat exchanger 100 again via the second outlet line AA2. The second medium M2 is distributed to and collected again from the second openings (not shown) of the plates P1, P2 via the channels APK in the upper cover plate OAP. This allows the media M1, M2 to transfer heat to one another. Due to the higher pressure of the second medium, the diameter of the second inlet line ZL2 and the second outlet line AL2 is smaller than the diameter of the first inlet line ZL1 and the first outlet line AL1, respectively. The first medium M1 can be a coolant consisting of water and ethylene glycol. And the second medium M2 can be a refrigerant; the use of carbon dioxide (R744) as the refrigerant is preferably provided. List of reference symbols 100 inventive heat exchangers P1, P2 inventive plates of the first type and of the second type S1, S2 inventive beads of the plates K1, K2 channels created between the plates according to the invention HD1, HD2 hydraulic diameter of the channels according to the invention O11, O21 first openings of the plates according to the invention O12, O22 second openings of the plates according to the invention D1, D2 Dome surrounding a second opening RA Circumferential raised edge of the plates according to the invention B1, B2 Floor plane of the panels according to the invention SO11, SO21 Guide bead of the plates according to the invention KV1 first guide channels between two adjacent plates M1, M2 Media flowing through the heat exchanger according to the invention on two fluidically separated flow paths H Main flow direction SR stacking direction QR transverse direction LR longitudinal direction OAP upper cover plate of the heat exchanger according to the invention UAP lower cover plate of the heat exchanger according to the invention OPK channel in the upper cover plate ZL1, ZL2 supply line for the media AL1, AL2 Drain line for the media QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2004 036 951 A1

[0002]

Claims

[1] Heat exchanger (100) preferably for a motor vehicle comprising: - at least one first plate (P1) - at least one second plate (P2) - wherein the at least two plates (P1, P2) each have a base plane (B1, B2) - wherein the at least two plates (P1, P2) are arranged alternately one above the other or next to each other - wherein the heat exchanger (100) is flowed through by two media (M1, M2) on two fluidically separated flow paths, so that the two media (M1, M2) can transfer heat to each other, characterized byin that the at least two plates (P1, P2) each have a plurality of beads (S1, S2), which each extend in an extension direction away from the base plane (B1, B2), wherein the beads (S1, S2) are each spaced apart from one another, so that channels (K1, K2) are formed between two adjacent plates (P1, P2) each having at least one hydraulic diameter (HD1, HD2) when the heat exchanger (100) is assembled, wherein the hydraulic diameters (HD1, HD2) change along the length of the channels (K1, K2), wherein the hydraulic diameter (HD1) of the first channels (K1) is greater than the hydraulic diameter (HD2) of the second channels (K2). [2] Heat exchanger (100) according to claim 1, characterized by that the beads (S1, S2) each have an elongated shape. [3] Heat exchanger (100) according to claim 1 or 2, characterized bythat the beads (S1, S2) are each arranged essentially in rows parallel to the main flow direction (H) of the two media (M1, M2). [4] Heat exchanger (100) according to claim 1, 2 or 3, characterized by that one of the beads (S1, S2) is offset from the adjacent beads (S1, S2) in and / or against the main flow direction (H). [5] Heat exchanger (100) according to one of the preceding claims, characterized byin that the at least two plates (P1, P2) each have at least one first opening (O11, O21) which is arranged in a first flat part of the base plane (B1, B2), wherein in each case at least one first guide bead (SO11, SO12) runs to the at least one first opening (O11, O21), which in each case extends in the direction of extension away from the base plane (B1, B2), so that first guide channels (KV1) are formed between two mutually adjacent plates (P1, P2), via which first guide channels the first medium (M1) is distributed to the first channels (K1) and collected again when the heat exchanger (100) is assembled. [6] Heat exchanger (100) according to one of the preceding claims, characterized bythat the at least two plates (P1, P2) each have at least one dome (D1, D2) which extends in the direction of extension away from the base plane (B1, B2), wherein the at least one dome (D1, D2) surrounds a second opening (012, 021), wherein at least one of the beads (S1, S2) runs to the at least one dome (D1, D2), so that the second medium (M2) is distributed to the second channels (K2) and collected again when the heat exchanger is assembled. [7] Heat exchanger (100) according to one of the preceding claims, characterized by that the first hydraulic diameter (HD1) is at least twice as large as the second hydraulic diameter (HD2). [8] Heat exchanger (100) according to one of the preceding claims characterized by that the at least one first opening (O11, O21) is larger than the at least one second opening (O12, O22). [9] Heat exchanger (100) according to one of the preceding claims, characterized by that the number of second openings (O12, O22) is greater than the number of first openings (O11, O21). [10] Heat exchanger (100) according to one of the preceding claims, characterized by that the first beads (S1), the at least one first guide bead (SO1) and the at least one first dome (D1) are each raised relative to the first base plane (B1) of the at least one first plate (P1). [11] Heat exchanger (100) according to one of claims 1 to 10, characterized by that the second beads (S2), the at least one second guide bead (SO2) and the at least one second dome (D2) are each recessed relative to the second base plane (B2) of the at least one second plate (P2). [12] Heat exchanger (100) according to one of the preceding claims, characterized bythat the first flat parts of the bottom plane (B1, B2) of two adjacent plates (P1, P2) are each connected to each other when the heat exchanger (100) is assembled. [13] Heat exchanger (100) according to one of the preceding claims, characterized by that the at least two plates (P1, P2) each have a circumferential raised edge (RA), wherein the edges (RA), the beads (S1, S2), the guide beads (SO1, SO2), the floor planes (BE1, BE2) and the domes (D1, D2) of two adjacent plates (P1, P2) are connected to one another. [14] Coolant circuit and / or refrigerant circuit for a motor vehicle comprising at least one heat exchanger (100) according to at least one of claims 1 to 13.

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